<template>
	<view class="content">
		<view class="mix-tree-list">
			<block v-for="(item, index) in treeList" :key="index">
				<view class="mix-tree-item" :style="[{
							paddingLeft: item.rank*15 + 'px',
							zIndex: item.rank*-1 +50 ,
							backgroundColor: active === index ? '#d5e8fc' : '#ffffff'
						}]" :class="{
							border: treeParams.border === true,
							show: item.show,
							last: item.lastRank,
							showchild: item.showChild
						}" @click.stop="treeItemTap(item, index)">
					<image class="mix-tree-icon"
						:src="item.lastRank ? treeParams.lastIcon : item.showChild ? treeParams.currentIcon : treeParams.defaultIcon">
					</image>
					{{item.name}}
				</view>
			</block>
		</view>
	</view>
</template>

<script>
	const currentIconUrl =
		"";
	const defaultIconUrl =
		"";

	export default {
		props: {
			list: {
				type: Array,
				default () {
					return [];
				}
			},
			params: {
				type: Object,
				default () {
					return {}
				}
			}
		},
		created() {
			this.treeParams = {
				...this.treeParams,
				...this.params
			};
			this.renderTreeList(this.list);
		},
		data() {
			return {
				treeList: [],
				treeParams: {
					defaultIcon: defaultIconUrl,
					currentIcon: currentIconUrl,
					lastIcon: '',
					border: false
				},
				active: -1
			}
		},
		watch: {
			list(newValue, oldValue) {
				this.treeParams = Object.assign(this.treeParams, this.params);
				this.renderTreeList(newValue);
			}
		},
		methods: {
			//扁平化树结构
			renderTreeList(list = [], rank = 0, parentId = []) {
				list.forEach(item => {
					this.treeList.push({
						id: item.id,
						name: item.name,
						parentId, // 父级id数组
						rank, // 层级
						showChild: false, //子级是否显示
						show: rank === 0 // 自身是否显示
					})
					if (Array.isArray(item.children) && item.children.length > 0) {
						let parents = [...parentId];
						parents.push(item.id);
						this.renderTreeList(item.children, rank + 1, parents);
					} else {
						this.treeList[this.treeList.length - 1].lastRank = true;
					}
				})
			},
			// 点击
			treeItemTap(item,index) {
				let list = this.treeList;
				let id = item.id;
				//点击最后一级时触发事件
				this.$emit('onSelect', item,index);
				this.active = index;
				item.showChild = !item.showChild;
				list.forEach(childItem => {
					if (item.showChild === false) {
						//隐藏所有子级
						if (!childItem.parentId.includes(id)) {
							return;
						}
						if (childItem.lastRank !== true) {
							childItem.showChild = false;
						}
						childItem.show = false;
					} else {
						if (childItem.parentId[childItem.parentId.length - 1] === id) {
							childItem.show = true;
						}
					}
				})
			}
		}
	}
</script>

<style>
	.mix-tree-list {
		display: flex;
		flex-direction: column;
		padding-left: 30upx;
	}

	.mix-tree-item {
		display: flex;
		align-items: center;
		font-size: 30upx;
		color: #333;
		height: 0;
		opacity: 0;
		transition: .2s;
		position: relative;
	}

	.mix-tree-item.border {
		border-bottom: 1px solid #eee;
	}

	.mix-tree-item.show {
		height: 80upx;
		opacity: 1;
	}

	.mix-tree-icon {
		width: 26upx;
		height: 26upx;
		margin-right: 8upx;
		opacity: .9;
	}

	.mix-tree-item.showchild:before {
		transform: rotate(90deg);
	}

	.mix-tree-item.last:before {
		opacity: 0;
	}
</style>
